#include<stdio.h>
int fact(int x); 
int main(void){
	int m,n;
	scanf("%d %d",&m,&n);
	printf("result = %d",fact(n)/(fact(m)*fact(n-m)));
	return 0;
}
int fact(int x){
	int i,y=1;
	for(i=x;i>0;i--){
		y*=i;
	} 
	return y;
}
